Limestone from the Jurassic Period (135-195 million years ago) has been quarried from the Isle of Portland for centuries. It was used extensively during the rebuilding of London after the Great Fire of 1666, and was the main construction material in St Paul's Cathedral and the Houses of Parliament.

In Grimm's day, the stone was extracted by groups of maybe three to five men, each group working virtually on a self-employed, "piecework" basis. The more rock extracted, the more money earned. The work was, unsurprisingly, incredibly difficult and demanding, with no advance in technology to make the task easier until well into the 19th century.

Once extracted from the ground, the stone would be transported to the sea for its onward journey by horses and the low-lying trolleys seen here. This method became obsolete with the arrival of the railway in 1902.